Piston ring



April 30, 1935. A. P. FALL 1,999,233

' PISTON RING Filed NOV. 19, 1931 E441 axe/z ,2 92/1.

Patented Apr. 30, 1935 l UNITED STATES PATENT OFFICE I i rrs rix ivoAlberti. Fall, Toledo, Ohio Application November 19, 1931, Serial No.576,090

7 Claims. (Cl. 309-45) The present invention relates to piston rings inthe accompanying drawing and the views thereand particularly to ringsfor internal combustion of are as follows: engines of the oil regulatingtype for eifectively' Figure'l is a vertical sectional'view illustratingremoving excess lubricant from the cylinder wall a fragmental portion ofa cylinder with a piston and also for preventing oil pumping. thereinwhich is supplied with a ring embodying 5 An object of the presentinvention is to proprinciples of the present invention. vide a pistonring so constructed as to provide a Figure 2 is a fragmental enlargedvertical secpositive seal between the piston and cylinder tional Viewthrough a portion of a cylinder, a pisthereby eliminating excess oilconsumption at all ton, and a ring embodying principles of the presmspeeds. Y ent invention. Another object of the invention is to providea. Figure 3 is a view similar to Figure 2 showing piston ring having avertically separated groove a ring reduced in radial thickness andinstalled and slot construction whereby oil may betrapped in a pistongroove with an expander or inner in a groove on one stroke of the pistonand passed ring.

1a through the slot in another stroke of the'piston. Figure 4 is anelevational view, partially in sec- Y A further object of the inventionis to provide tion, of a piston ring embodyin -principles of the apiston ring having an edge eifective for scrappresent invention. ingaction on the-downstroke and another edge Figure 5 is a view similar toFig. 4 showing effective for scraping action on the upstroke anotherembodiment of the present invention. whereby'excess oil may be gatheredand eventual- The piston rings of the present invention are 20 lydrained thereby aifording improved lubrication. particularly for servicein connection with in-, A stillfurther object of the invention is toproternal combustion engines although of course Vide a Piston ring havina oo for C llec ng such rings may be used with other prime moverstherein oil on downstroke and thus effectively lu and accordingly arenot to be restricted to interbricating the relatively movable parts. nalcombustion engines. 25

Another and yet further object of the inven- The drawing will now beexplained. tion is to provide a piston ring having a plurality An enginecylinder l is shown having a piston of bearing surfaces for engaging thecylinder wall 2 reciprocable therein. The piston is provided thusinsuring a uniform pressure against the 03 1- with, in the presentinstance, three ring grooves inder wall and lengthening the life of thering. 3, 4, and 5 for the reception of piston rings as is 30 Another andstill further object of the invention c mmon practice. g is to provide apiston ring so constructed with Th lowermost ring groove 5 is providedwith grooves and Openings as to maintain P per wall a, plurality ofopenings 6 extending from the I tensieninserv e rear portion of thegroove and opening to the Another and further object of the invention isi t ri f th piston and serving as drains for 35 to provide an oilregulating ring having drain l bri t in the ring groove 5. op ningsthrough the Same arranged near the hot-a Installed in the grooves 3 and4 are conventom of t e ri d a groove recess above the tional pistonrings! and 8, while installed in the openings for accumulating excesslubricant. groove 5 is a piston ring 9 embodying principles 40 Anotherobject of the invention is to provide a of the present invention. 40piston ring having a single series of elongated The ring 9 installed inthe groove 5 of the'pisslots extending through the ring and disposednear ton 2 may be the form illustrated in Figure 4 or the bottom thereoftogether with a recess above the form illustrated in Figure 5. some ofthe slots for accumulating therein ex- Referring to the ring illustratedin Figure 4 it cess lubricant, the ring being so c nst d as will beobserved that the ring is provided with a 45 to redue t CylinderContacting surfaces '50 single series of circumferentially spaced slotsIll imum area and at the same time capable of ex r disposed nearer thebottom face' I I of the ring. me Substantially uniform pressure ainstthe These slots are preferably wider at the outer porcylinder wallthroughout the circumference of the ti n th n the inner due to themanufacturing ring. process. Above the series of slots l0 appear a 50The ab ve, r, nd further bjects of the plurality of circumferentiallyspaced recesses or inventio Will. be apparent from the following (1grooves l2 formed by undercutting the ring in the scription,accompanying drawing, and appended outer surface thereof providing ashoulder or claims. scraping edge I3, an upper wall ll of the recess '55Embodiments of the invention. are illustrated or groove and an inclinedwall l5. The walls I5 incline downwardly and outwardly terminating in anedge l6 which may lie in the surface of the cylinder wall contactingportions of the ring.

The edge I6 is at substantially mid-height of the ring. The grooves orrecesses l2 at the split 'II are not closed adjacent such slit but areopen lation as illustrated in Figure 4, the recess in one end of thering atthe split will open into and communicate with the recess in theother end adjacent the split thus forming a continuous groove across thesplit. The spaces, recesses or grooves l2 are separated by bridges l'lformed by i a suitable tool when the recesses are made.

The edge l6 may be coincident with the cylinder wall engaging surfacesof the ring or may be slightly less. In any event this edge is fine andunder conditions of use lubricant passes over this edge from a recess toa slot or opening.

The ring illustrated in Figure 5 is provided with a similar series ofcircumferentially spaced openings or slots 18 formed in the ring nearerthe bottom surface or face ll of the same. Above the openings I isformed a continuous groove or recess I8 open at the ends adjacent thesplit l9 to form in effect a continuous groove or recess about the outerface of the ring and nearer the upper surface 26 of the same. The grooveor recess is formed by undercutting providing a scraping edge 2|, asubstantially horizontal top wall 22 and an inclined side wall 23 thelatter being inclined downwardly and outwardly and terminating in anedge 24 which may be slightly less in diameter than the cylinder wallengaging portions of the ring such for instance as the scraping edge 2|.

Figure 2 illustrates a fragmental portion of a piston 2 with a ring 9therein embodying principles of the present invention and showing anopening I0 through the ring communicating with an oil drain passage 6formed in the piston. Above the opening it] isa recess or groove desig--nated at 25 which may be a portion of the continuous groove iii of thering of Figure or a portion of one of the grooves [2 of the ring ofFigure 4.

Figure 3 illustrates a fragmental portion of a piston 2 having a ring 26therein embodying principles of the present invention but reduced inradial thickness to allow the installation of an expander or innerspring 21 between the inner surface of the ring and the-rear wall of thegroove. Oil drain passages 6 are provided and also the ring 26 isprovided with openings ID for oil drain purposes and a recess 28 whichmay be of the character of the recesses l2 of the rings In operation aring constructed in accordance with the principles of the presentinvention will on the downstroke of the piston scrape surplus oil on thecylinder wall into the groove or recess or beveled channel by reason ofthe scraper edges I3 or 2!. On the upstroke the oil drains down on thebeveled inclined walls l5 or 23 and is distributed on the cylinder Walluniformly thus giving perfect lubrication. Any excess lubricant or oilthat there may be passes down about the reduced circumferential diameterof the, edge 24 or I6 into the openings I0 thence rearwardly through thering into the piston ring groove 5 and subsequently through the drainports 6 to the crankcase.

- It will be observed that use of rings embodying the present .inventionis such as to collect excess oil in the beveled channels on thedownstroke of the piston and to excess oilinto the openings below suchchannels for return to the crank- .case through the holes in the pistonleading from the piston ring grooves.

The provision of the beveled channels affords constant lubrication atall points on the cylinder wall without obstructing any part of the ringso that perfect lubrication is effected.

Removal of the metal to provide the beveled channels or recesses and theslots removes a sufficient amount of metal from the ring whereby thering instantly seats after installation in a piston ring groove in apiston.

The provision of the bridges H in the form of ring illustrated in Figure4 is proportioned to divide the ring equally as to the beveled channelsso that uniformity of pressure on all portions of the cylinder wall ismaintained and at the same time affording sufficient wearing surfaces inthe ring to prolong the life of the same.

Rings constructed in accordance with the present invention do not havethe wall tension thereof reduced even though large quantities of metalbe cut away from the face of the ring in forming the rings ,of thepresent invention.

The provision of the two scraping edges for picking up excess oil inaddition to the oil or lubricant in the beveled channel together withthe escape of excess oil through the openings of the ring vent to thecrankcase affords a positive seal between the piston ring and cylinderwall and eliminates excessive oil consumption at all speeds and at thesame time creates an oil film between the cylinder wall and face of thepiston ring that assures constant lubrication.

Rings of the present invention may be used with or without expanders orinner rings. If usedwith expand'ers then the radial thickness of therings will be reduced slightly to accommodate the insertion of theexpanders behind the piston rings in the piston ring grooves.

The advantage of disposing the beveled channels or oil collectingrecesses or grooves above the openings is that better lubrication isassured and collection of excess oil is accelerated, thus preventing oilpumping and increasing the efllciency of the internal combustion engine.

The top and bottom surfaces of the openings l0 are parallel whereas theend portions of these openings converge inwardly.

When the ring is constructed as illustrated in Figure 4 the channels andopenings are so arranged relatively to one another that a recess orchannel communicates with one or more of the openings through the ring.

The edge l6 cuts through the film of oil on the cylinder wall.

The invention has been described herein more or less precisely as todetails yet it is to be understood that the invention is not to belimited thereby, as changes may be made in the arrange ment andproportion of parts and that equivalents may be substituted withoutdeparting from the spirit and scope of the invention.

The invention is claimed as follows:

1. A piston ring having an undercut recess formed in the outer surfacethereof near the upper face of the ring, the top surface of the undercutrecess providing a scraping edge for the downstroke of the ring inservice, said ring having a. series of elongated openings therethroughbelow said recess, the lower portions of said openings constitutingscraping edges on the upstroke of the ring in service, said recesshaving a downwardly and outwardly extending side wall which merges intothat portion of the ring forming the tops of said openings, said recessand openings being out of communication for oil interchange except overthe edge of said recess side wall.

2. An axially rigid piston ring having upper and lower faces and havingan imperforate circumferentially extending groove in its outer'peripheryundercut therein and spaced below the upper face of the ring, said ringhaving a plurality of circumferentially spaced radial openings ofuniform height and shape therethrough below said groove, said openingsopening through the outer surface of said ring above its lower face, thelower surface of said groove being downwardly inclined and lyingimmediately above said openings, and the upper surface of said groovebeing below and parallel to the upper face of the ring.

3. An axially rigid piston ring having upper and lower faces and havinga circumferentially extending groove in its outer periphery undercuttherein and spaced below and near the upper face of the ring, the lowersurface of said groove being downwardly inclined and merging with theouter periphery of said ring at substantially midheight thereof, saidring having a plurality of circumferentially spaced radial openingstherethrough below said groove and opening through the outer surface ofsaid ring above its lower face, the outer edge of the upper surface ofsaid groove providing a scraping edge active on down stroke, and theportions of the ring circumferentially spacing said openings and theportions of the ring below said openings lying in of the ring.

4. An axially rigid piston ring having a circumferentially extendinggroove undercut in its periphery below the top face of the ring, theouter edge of the topsurface of said groove providing a scraping edgeactive on down stroke, the lower surface of said groove being inclineddownwardly, and said ring having a plurality of elongatedcircumferentially spaced radial openings therethe outer peripherythroughimmediately below the lower edge of said inclined groove surface, saidopenings lying above the bottom face of said ring, and a part of theouter ring face below said openings adapted to contact the cylinderwall.

5. A piston ring having an undercut recess or groove in its outersurface below the top face.

of the ring, the outer edge of the top surface of said recess or grooveproviding a scraping edge active on down stroke, the lower surface ofsaid recess or groove beingdownwardly inclined, said ring havingcircumferentially spaced openings therethrough below said inclinedsurface of said groove, the portions of the ring spacing said openingslying in the outer surface of the ring and bridging the ring between thelower part thereof and said inclined surface of the groove or recess,

downwardly and outwardly inclined beveled face merging into said slits.

'7. A piston ring comprising a resilient split band having a pluralityof slits extending radially therethrough and separated by bridgeportions connecting the upper and lower portions of the band, the saidband also being provided with a single series of circumferentiallyspaced imperforate grooves lying below the top face of the ring and eachhaving a downwardly and outwardly inclined face merging into said slits,the toe of said beveled face being adapted to be out of contact with thecylinder wall for oil interchange between said grooves and said slits inservice.

ALBERT P. FALL.

